Current-tapping cap-plug fitting and the like attachment devices



June 3, 1941. J. PETRY 2,244,527

\ CURRENT-TAPPING CAP-PLUG FITTING AND THE LIKE ATTACHMENT DEVICES Filed Nov. 5, 1940 2 Sheets-Sheet l 23a '12b 20a ATTO R N EY J. PETRY June 3, 1941.

CURRENT-TAPPING CAP-PLUG FITTING AND THE LIVKE vATTACHMENT DEVICES 2 SheetsSheet 2 Filed Nov. 5, 1940 INVENTOR JOHN PET/Qy BY ATTO R N EY Patented June 3, 1941 URRENT-TAPPING CAP-PLUG FITTING AND THE LIKE ATTAJCHIVIENT lDEVICES John Petry, Flushing, N. Y., assigner to Raylite Trading Co., Inc., a corporation of New York Application November 5, 1940, Serial No. 364,392

(ICI. 173-6334) 8 Claims.

This invention relates to electric attachment ittings, such as cap-plugs, and as here shown are incorporated in an improved construction of a combination current-tapping, cap-plug litting for detachably connecting one or a plurality of portable electric appliances, lighting systems and the like to an electric power supply outlet receptacle.

Among the objects of the invention is to generally improve electric attachment fittings of the character described, whereby such fittings shall comprise few and simple parts assembled to form a neat appearing, compact, rugged structure, which shall be cheap to manufacture, and which shall be practical and efficient to a high degree in use,

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists in the features of construction, combinations of elements and arrangement of parts which will be exemplilied in the constructions hereinafter described and of which the scope of application will be indicated in the following claims.

In the accompanying drawings, in which is shown various possible illustrative embodiments of this invention:

Fig. 1 is a side elevational View of a combination current-tapping cap-plug fitting connected with a cap-plug shown in section to expose the interior construction embodying the invention;

Figs. 2 and 3 are an end and front elevational View of the combination current-tapping capplug fitting shown in Fig, l, part of the body portion of the fitting in Fig. 3 being broken away to show the expansion anchorage of the current carrying contact terminal blades or prongs;

Figs. 4 and 5 are cross-sectional views taken on lines 4--4 and 5 5 in Fig. I, respectively;

Figs. 6 and 7 are perspective views of the current carrying contact terminal blades or prongs, and the current carrying spring contact, respectively;

Fig. 8 is an end View of the improved fitting similar to Fig. 2 showing a modified construction of the invention using screw binding posts instead of soldered connections for the conductor wires;

Fig. 9 is a perspective view of a terminal blade or prong with the screw binding post differing from that shown in Fig. 8; and

Fig. 10 is a cross-sectiona1 view taken on lines lll-l0 in Fig. l showing details of the invention incorporated in the cap-plug tting.

Referring in detail to the drawings, 2t denotes an improved combination current-tapping, capplug fitting constructed to embody the invention adapted to connect with conventional base boards and fixture socket or iiush outlet receptacles in the well understood manner, such improved iittings 20 having their current-tapping portions adapted to connect with other fittings 30, or with contact terminal blades or prongs 22 of a capplug 30 constructed to incorporate certain features of the invention hereinafter described and shown in Figs. 1 and 10, or similarly connected with contact terminal blades or prongs of any standard cap-plug fitting (not shown) in the well known conventional manner.

Any such conventional cap-plug or cap-plug 30 shown in Figs, 1 and 3 may terminate the ends of conductor wire 3i for connecting an electric appliance (not shown) to a suitable power source through the improved current-tapping cap-plug fitting 20 in the well understood manner.

The fitting 20 preferably comprises a one-piece body portion 2| of any suitable shape and formed of insulating material, such as a so-called plastic, as for example a phenol-condensate material or the like moldable substances which form rigid structures. As here shown, the body portion is cylindrical and has current-carrying members mounted and secured in the manner hereafter described at spaced diametrically opposite portions of the wall of said body portion 2l inwardly from the peripheral rim Zia thereof as shown in Figs. 1 and 3.

The current carrying members may comprise terminal blade portions 22 extending outwardly from the rear end open side 29a of the fitting body portion 2l and spring contacts 23 which electrically connect with end bases 22a of the blades 22 when assembled in the body portion 2 l, Said spring contacts 23 extend into a pair of spaced parallelly aligned passages 2lb provided in the body portion 2| and communicating with the rear end open side Zila of the fitting 20. Said passages 2lb project in from openings 2Ic provided in the front end closed side 26h of the fitting 2li opposite said rear end open side 26a, said passage openings 2l@ being shaped and sized to permit the free insertion of blades or prongs 22 of cap-plug 30 or other similar or conventional plugging-in device. The passages 2lb may be made the same width as the openings 2 lc but are slightly larger in breadth to accommodate the breadth of the spring contact 23, said passages 2lb being somewhat longer than the length of the plugging-in portion of the blades or prongs 32 so that on insertion of the latter in fittings Z, a small clearance is provided as is clearly shown in Fig. l.

Adjoining each passage 2lb and extending in from the open rear side Zila only partially the length thereof, there is provided a socket or cavity 2id. Each socket or cavity 2id may if desired be separated from the adjoining passage 25h by oppositely extending ledges 2te formed in the common wall therebetween asI part of the body portion 2l, and the bottom or dead endV of each cavity 2id may be provided with a suitable cam means such as a protuberance or wedge 2U integrally molded as part of the body portion 2l. See Figs. 3, 4 and 5. The side wallsA Zigv of said sockets 2id extend parallelly in from the open rear side 29a, the width of said socket preferably being enlarged at the inner, ends of the side walls Zig, that is, cut back for a length substantially equal to the wedge Zig to provide shoulders 2lb. and anchoring pockets for expanded split end bases 23a of blade portions 22 as shown in Fig. 3 and in the manner hereinafter described.

As shown in Figs. 1 and 6 the blade portions 22 may be constructed of a metal stamping having the usual circuit connecting prongY end 22h and provided with an offset 22o midway the prong end 22o and end base 22a. The latter is split centrally up to the offset 22C to provide spaced tongues 22d and the outer surfaces of said tongues may be out as at E23 to provide spurs 22j which The spring contacts 23 preferably be made of a copper sheet metal strip bent to have a right triangular shape and formed with one corner portion detached at 23o as shown in Fig. 7. Such construction permits the adjoining and Opposite sides 23p and 13o, respectively, thereof, to be flexed with respect to the other side 23d when QD- erative as shown in Fig. i. The side 23d may be provided with a lip or flange Zlio, the4 exterior side of said lip 23e being adaptedin the assembled fitting 2B, to abut and Contact the tongues 22d of the blade end base 22a.

The lips or flanges 2de, initially are bowed across the width thereof as shown` in Fig. 'l which on being assembled gives an extra spring con struction to provide an efficient electrical contact, twobosses 23g, may be provided for producing a scraping action on being assembled, as is clear from Fig. l. The lip or flange 2te with the adjacent adjoining side 23o provides another function, namely, the clamping between them the ledges i2 le during the process of assembly to avoid accidental displacement of said spring contacts 23 from the passages 2lb and prior to inserting the blade base 22a, in sockets 2id for mounting and securing the blades 22 in anchored position.

To provide an unbroken peripheral rim 2 ici about the open side 39a of the tting 2@ yet allow conductor wires 2t to extend through the side Wallof the body portion 2l an opening 2 ij is provided. To this end, the rim 2id is made larger in diameter than the portion of the body` portion extending down from the closed side iib. above said rim and thus forms a projecting rimband- The inner wall of said rim-band preferably aligns with the adjoining outer. wall portion thereabove, as is clearly shown in Fig. i'. Thus in molding the body portion El. the mold may have a core pin (not shown) extending up into. the open side 29a. and terminating in aform to produce the opening 21.0, yet leaving the rim 22a continuous. and unbroken.

As was described above, the Width of sockets 2Id are enlarged at the inner end walls 21g to provide the shoulders 2| h. This construction can be readily provided during the molding operation of the body portion 2i by a so-called stripping step, that is, by using core portions of the mold (not shown) which form sockets 2|d having enlarged ends corresponding to the contour forming the shoulder 2lb and by removing such core from the molded body portion 2l While it isA still hot and in an expanded condition. The enlarged ends of such core may be slipped out, that is, stripped out so that when the hot molded body portion 2l cools and hardens, the under cut anchoring pockets with shoulders Zlh are produced as: shown in Fig. 3.

From the above description and the drawings, the invention will now be apparent. After constructing the molded body portion 2|, terminal blades 212 and spring contacts 23, as shown in Figs. l to 3, 6 and 7, the assembly operation of the fitting is quite simple to accomplish. First, the spring contacts 23 are inserted in the passages 2lb of the body portions 2lk where they are retained against displacement during assembly operation by the clamping of the ledges Ele between flanges 23e and spring Contact side 23o. Next the end bases 22a of the blades 22 are inserted in the sockets 2id. Since the width of these end bases 22a are made substantially the Width of the sockets 2 ld and as there may be only a slight give to the tongues 22d, very` little pressure and force is necessary to start the entry of end bases 22a into the sockets 2 id. When the tongues 22d reach the level of the wedges 2 if, the latter enters the splits in the end bases 22a and cam the tongues 22d laterally into the pockets and under the shouldersi Zig making an irremovable firm anchorage without scoring or otherwise scratching the Walls ofv the sockets other than tightly squeezing or perhaps biting the spurs 22j into the pocket walls to form a rigid attachment.

It should be noted that the splits provided inl end bases 22a to form the tongues 22d are of substantial width which are carried up to the offset portions Zic. and the cut-out portion 22e forming the spurs 22j further reduce the cross-sectional area of the tongues 22d to increase the` elective resilience thereof asis clear from Figs. 3 and 6.

Simultaneously with the insertion of the end bases 22a into the sockets 2 ld, as above described, the bowedV flange 23e contacts the flat side surfaces of the tongues 22d causing the bosses y23p to make an eicient scrapingr electrical contact therewith on inserting the end bases 22a in final anchored position. As shown in Figs. l and 3, the Width of each socket 2id is made to just accommodate the thickness of the tongue 22d andk the flange 23e, the latter being flattened from its initial bowedcondition during the inserting operation.

The current carrying contact members having been securely anchored in the body portion 2l, it completes the fitting 25 which now may have connected therewith4 the conductor Wires24 which have the ends thereof passed through opening 2li. It will be noted that in fitting 2l).A the bared ends of wires 24 may be soldered to the current: carrying member as at 25 on the vblade osetY portion 22o, such soldered joints being found more practical, efficient and reliable than clamped or screw binding post terminals for apparatus having radio circuits, Christmas lighting units and other portableiappliances.

Where it is desirable to provide screw binding post terminals instead of solder joints 25, blades |22 may be provided which are similar in construction to blades 22 shown in Fig. 6 With the exception that offset portion |220 of blades |22 are provided with ears or extensions |227' which carry binding post screws |22k for electrically connecting the conductor wires Eli thereto as shown in Fig. 8.

In Figs. 1 and 1G the novel combination of blades and body portions are shown in combination for providing the plug caps 3d. Here conductor wires 3d pass into the body portion 3i preferably through the rounded closed front side 30h opposite the rear open side 3Go and connect with the blade members 22 which are permanently anchored in socket 3|d in the identical manner described above for fitting 22 and as shown in Fig. 1.

Since cap-plugs 3Q are not intended to provide an extra current-tapping means incorporated therein, which the spring in contacts 23 in passages 2lb, etc. form in fitting 2 I, such spring contact and passage constructions, etc, are omitted and the conductor wires 3d may be soldered to base offset portions 22C at 35.

Where binding post terminals are required, the solder joint 35 may be replaced by screw binding posts |327c threaded directly into the odset portion 22e as shown in Fig. 9, such construction permitting body portions 3| of fittings 30 to be made smaller than would be otherwise possible.

It will thus be seen that there is provided means whereby the several objects of this invention are achieved and which are well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiments above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. An electrical fitting of the character described comprising a rigidly molded body and terminal contact blade members mounted to eX- tend therefrom, said body having an opening extending in from one side thereof and parallelly aligned sockets spaced from said opening extending in from another side of said body, said sockets having under cut pockets at their inner ends, a conductor wire passing through said opening and electrically connecting with the blade members, said blade contact members having expandable bases each being decreased in cross-sectional area at a mid-portion to enlarge an end thereon fitted into said sockets, camming means forming part of the walls of said sockets for engaging and expanding said base ends so constructed and arranged that said expanded contact end portions grip the ends of said bases beyond the mid-portions thereof occupying said pockets for irremovably anchoring the blade members in rigid mounted positions.

2. In an electric fitting of the character described, a spring contact current carrying member formed of a strip of material bent into a right triangular shape structure with one side thereof disconnected from the adjacent side at a corner, and a ilange formed from an edge portion of one of said sides at the corner, said flange and the disconnected adjacent side forming a clamp retaining means for resiliently engaging therebetween a body portion of the tting while two adjacent sides of the structure may be flexed with respect to the remaining side.

3. In an electric fitting of the character described, a spring contact current member defined in claim 2 in which said flange is bowed outwardly to increase its resiliency.

4.. In a cap-plug construction of the character described having a terminal blade formed with a base, a spring contact of a current carrying member of triangular shape having one corner portion thereof detached to permit the adjoining and the opposite side of said member to be flexed with respect to the other side, said last mentioned side having a flange extending in the direction of said adjoining side for contacting the exterior surface thereof with said terminal blade base, said flange and adjoining side resiliently engaging therebetween a body portion of the cap-plug.

5. In the cap-plug construction of the character described, a spring contact defined in claim 4 in which `said flange is bow'ed and provided with scraping means for increasing said contacting eiect between the flange and the blade base.

6. In an electric iitting construction of the character described, a rigidly molded insulating body formed with spaced passages extending therethrough and sockets extending in from` one side of the body part way therethrough alongside the passages, ledges provided in the common wall between said passages and sockets, spring contact current carrying members fitted in said passage, said members having clamping means engaging the ledges, current carrying terminal contact blades having expandable base ends anchored in said sockets, cam means projecting from parts of the wall of said sockets for expanding the base ends on inserting the latter fully in the sockets for making the anchorage of the blade members in the sockets irremovable, parts of said clamping means being so constructed and arranged to contact with the blade base ends in the sockets.

7. In an electric fitting construction of the character described, a rigidly molded insulating body formed with recessed portions or sockets extending in from a side thereof and passages extending alongside said sockets through said body, current carrying terminal contact blades having expandable base ends anchored in said f sockets, cam means projecting from parts of said socket walls for expanding said base ends on inserting the latter fully in the sockets for making the anchorage of the blade members in the sockets irremovable, spring contact current carrying members of triangular shape fitted in said passages, said spring contact members having one corner of each detached to perm-it the adjoining and the opposite sides of each member to be flexed with respect to the remaining side, said remaining sides having iianges facing the passages for contacting the exterior surface of the lianges with bladebase ends in said sockets.

8. In the electric fitting construction defined in claim 7, the flange being bowed outwardly to provide spring pressure of the contact of said flange surface with the blade base ends.

J OHN PETRY. 

